Air-regulating valve



Nov. 1, 1927.

J. J. STOETZEL AIR REGULATING VALVE Filed June 30, 1924 ATTORNEYPatented Nov. 1, 1927.

UNITED STATES JOSEPH J. STOETZEL,

OF NEW YORK, N. Y.

AIR-REGULATING VALVE.

Application filed June 30,

My invention relates, more particularly, to valves which are used, inpneumatic despatch tube apparatus, or systems, for regulating the flowof air through such apparatus or system, to conform to the demands forquantity, or speed, of flow, created, by the presence in transit ofvaryingnumbers of carriers, by variations in the length of line, and bydischarge of various carriers. In modern practice it has been founddesirable to keep up a slight, or minimum, flow of air through thesystem when no carrier is in 1ine,such air being substantially atatmospheric pressure, and to be capable of attaining a full, or maximum,flow of air great enough to provide for a large number of carrierssimultaneously in transit,-.and so controlled, or regulated, that theactual flow at any time corresponds to the requirements or variations inflow caused by the introduction or discharge of any carrier when thereare other carriers in line.

The object of my inventionv is to provide such an air-regulating valvewhich is selfacting, in the sense that it does not require any so-calledoperating mechanism at all but swings, or slides, from a more-open to alessopen position, or vice versa, to permit less or greater passage ofair through the system, in response to changes in the force ordiflerential pressure of air, on opposite ends of the valve, somewhat asa weather-vane moves from point to point, in response to changes in thedirection of the air which blows upon the vane. In other words, I relywholly upon the difi'erential pressure or kinetic energy of the airflowing through the system, or, more definitely, flowing past the valve,as compared with the outside air to cause the valve to move in thedirection and to the extent, called for by the presence, absence,introduction, or discharge, or carriers, at each and every variation ofoperation of the pneumatic apparatus or system.

One form of my invention is shown in the accompanying drawing in whichFigure 1, is a vertical section.

Figure 2, is a perspective view of the valve-spool.

Same letters indicate similar parts in the different figures.

A, B, represent an exhaust tube of any system of piping, preferably apneumatic despatch tube system. It will be understood that the upperportion A, connects with the transit tubing, while the lower por- 1924.Serial N0. 723,407.

tion B, communicates with the exhauster. Connecting these two sectionsof exhaust tube is the casing C, which is open to the atmosphere, asshown, by a spider D, (in preference to a perforated cover or plate)with its hub containing a bearing cl, for supporting the valve rod E,and provided at the other end of the valve rod with a removable plateorcover F, the bushing of which serves as a bearing for the rod E, asshown, at that point. The casing C, is, preferably, divided. into twoparts, or chambers, G, H, by a partition J, through which is apassage-way, K, preferably circular, of a capacity to permit the maximumflow of air which it may be desirable for the system to attain.

It will be understood that this passage- I way K, is always open tosome, or to greater, extent, and that air 18 always flowing through inthe dn-ection of the arrows whenever the exhauster is in operation,whether 7 any carriers are in line or not. This flow varies therefore,from the minimum to the maximum, making a complete accommodation to thevarying calls made upon it by the insertion or discharge of carriers.

In this casing is located by improved airregulating valve, which isoperated pneu matically, without the use of any auxiliary operatingmechanism, either for opening or closing the valve. This valve consistsprimarily of a spool, one type of which is shown in Figure 2. In theform shown, the valve consists of a tube L, mounted on rod E which isadapted to slide easily, in either direction between its bearings at Dand F. This spool is provided at one end with a suitable plate or spoolendM, of a size sufficient to overlap the passageway K, and close itcomplete- 1y it allowed so to do,and at the other end with a plate orspool end of smaller diameter which cooperates with an adjustable, orflexible, plate or diaphragm, O, which automatically adjusts theeffective pressure area of that end of the spool so as to exert asagainst the pressure area of plate M, a greater pressure than thatofsaid plate, when it is required that the spool move toward the coverF, and exert a lesser pressure than plate M, when the spool is requiredto slide toward spider D. For convenience or' construction, andreplacement in case of wear, this expansible, or flexible plate is shownas made in two pieces, a, Z), the outer of which is made of leather orother flexible material and the inner of metal or other hardmaterial,but such two-part structure is not mechanically required as asingle piece of flexible material with a hardened centre may constitutethe spool end N if preferred.

The to and fro motion of the spool L is limited as follows The motion toclose the passage-way K, is preferably stopped at a predetermined point,as by set screw, 0, at bearing (Z-(Z, so that the plate M never closesthe mouth of the passage-way wholly, but leaves a channel between theplate and the passage-way of sufficient capacity to permit the desiredminimum flow before spoken of. A spring 6, of any desired construction,is preferably provided to aid the movement of the spool toward saidpartly closing point, and to resist gradually the movement of the spoolin the other direction,which is limited by set screw 0 in bearing F.

The flexible part of spool-end, N, is preferably circular and issteadied, stifiened, and held fast to the casing inside the spider D, byscrews, as at g, 9, so as to make a tight joint at its periphery.

It will be readily understood by those familiar with the art that myimproved airregulating valve is of extremely simple construction, andthat its operation is equally simple. This operation may be brieflydescribed. as follows lNhen there is no carrier in transit the partswill be as shown in full lines in Figure 1,the spool-end M, beingsufficiently away from the edge of the passage-way K to permit theconstant minimum flow as shown by the arrows. The spool-end N, will bestatically balanced between the atmospheric air which permeates thespider, and the air of the minimum flow which, of course, is alsoatmospheric.

Upon the insertion of a carrier anywhere in the system, the minimum Howof air is at once blocked, or cut off. The exhauster at once begins torarify the air which constitutes the minimum flow (practically thisrarification is almost instantaneous) and to build up a vacuum bysuction, so-called. Almost immediately the differential pressure on theouter side of spool-end N,that is, the difference between theatmospheric air filling the spider, and the rarifying air inside thecasing,causes the spool to slide toward the cap F and thus open thepassageway K, entrance wider, against the resilient force of spring 6.As the spool slides inwardly, the effective differential pressuresurface as shown in dotted line of the part a, of spool-end N.

WVhen the carrier passes out of the discharge-outlet, the sudden rush ofatmos pheric air which was driving said carrier from behind, strikes thespool-end M, praetically head-on, and adds its kinetic energy to theresilient force of the spring 6, to cause the spool to slide outwardlyagain into the position shown in full lines in Figure 1. Thisover-balancing of the atmospheric pressure constantly exerted againstthe outer area of spool-end N, is easily attained owing to thediminished effective pressure, area, above referred to. But as thespool-end N thus slides toward the spider E, this pressure areaincreases, returning to its original extent, and thus, by the time theusual minimum flow is reestablish-ed by the part-closing of thepassage-way K, the spool-end N, is equipoised as at the beginning.

Such is the operation when only a single carrier is inserted in the lineand is allowed to pass out through the discharge outlet before a secondcarrier is inserted. But, in practice, this is of comparatively rareoccurrence.

()ne of the great advantages of my improved valve is that by permittingthe spool a longer slide than would be necessary for the above describedaction of a single carrier, I am able to take care of as many can riersat a time as the line of tubing is capable of receiving. In such casethe first carrier inserted only causes the valve to slide, and thepassage-way K, to open, sufficiently to take care of that particularcarrier. Upon the insertion of a second and each subsequent carrier, theair-valve slides open a little further, thus enlarging the opening ofthe passageway accordingly, and as soon as the first carrier insertedleaves the line this relief of pressure permits the air-valve to slideback correspondingly towards its normal position. And the same is trueof every succeeding carrier until the last carrier has left the line.

It must be borne in mind that by the term .spool whether in claim ordescription, I mean any sort of member or device of whatever shape,which, is adapted to serve the purposes of the structure described andshown herein as a spool.-

I claim 1. In a regulating valve structure for a pneumatic dispatchtube, a valve chamber, a longitudinally slidable valve rod mounted inthe chamber and extending transversely of the tube, a cap member at eachend of the chamber in which the ends of the valve rod have slidingengagement a partition in said chamber provided with an opening throughwhich the valve rod passes, a disk valve carried by the rod and tendingto close the opening when moved in the direction of flow of air throughthe opening, a second disk carried by the rod on the other side of thepartition and spaced therefrom, a diaphragm closing the chamber andlocated adjacent to the position of the second disk said valve rodpassing through said diaphragm, and said diaphragm being exposed toatmosphere whereby upon a diminution of tending longitudinally of thetube to divide the valve chamber into two compartments, said partitionbeing provided with an opening through which the valve rod extends, a

' valve disk carried by the valve rod and mounted in one of saidcompartments to cooperate with the opening in the partition to open orclose the same, a disk member mounted on the valve rod in the othercompartment adjacent the outer end thereof, a flexible diaphragm closingthe outer end of the second compartment, said second disk having a lessdiameter than the diameter of the valve disk, and said flexiblediaphragm being exposed to atmosphere on its outer surface whereby upona diminution of pressure within the tube the diaphragm will engage theadjacent disk to move the valve rod and the valve disk carried therebyto open position to permit a flow of air to pass through the opening inthe partition.

3. In a regulating valve structure for a pneumatic dispatch tube, avalve chamber,

a longitudinally slidable valve rod mounted in the chamber and extendingtransversely of the tube, a sleeve carried by the valve rod, a partitionin said chamber extending longitudinally of the tube to divide the valvechamber into two compartments, a valve disk mounted on one end of thesleeve at one side of the partition whereby to open or close the openingin the partition, a spring engaging the valve disk and tending to movethe same to closed position, means for preventing the complete closingof the opening in the partition, a disk member mounted on the other endof the sleeve at the other side of the partition, a flexible diaphragmclosing the end of the valve chamber adjacent the second named disk,said flexible diaphragm being exposed to atmosphere on its outer surfacewhereby upon a diminution of pressure within the tube the diaphragm willengage the adjacent disk to move the connected valve disk to openposition, said diaphragm engaging a decreased area of the adjacent diskwhen the valve is in open position whereby to produce dilferentialpressure areas on opposite sides of the disk, whereby said differentialpressure areas in cooperation with the spring will operate to move thevalve into closing relation to the opening upon a rise of pressurewithin the tube.

JOSEPH J. STOETZEL.

